GLP-1 constipation: fiber, fluids and foods that help

Constipation is one of the most common side effects of a GLP-1 medication. It’s uncomfortable, and it’s not something you did wrong. A few food and drink habits often help, alongside your care team.

How common is it?

Common, and more likely while the dose is being increased.

The 2025 joint advisory from four nutrition and obesity medicine groups (ACLM, ASN, OMA and TOS) reports constipation in about 17 to 24% of trial participants. These medications slow how quickly food moves through your gut, and eating less overall means less fiber and fluid going in.

How much fiber do I need?

Most adults need about 22 to 34 grams a day, depending on age and sex.

That’s the range the NIDDK gives. On a smaller appetite it can be hard to reach, so it helps to pick foods that carry a lot of fiber in a small portion, rather than eating more.

How do I add fiber without feeling worse?

Slowly, a few grams at a time, with more to drink.

• Add one fiber food at a time. Give your body a few days to adjust before adding another. The advisory notes that very high-fiber foods can be harder in the first few days of a GLP-1.
• Drink as you go. Fiber works best with fluid. Water, tea and clear soups all count.
• Spread it out. A little at each meal sits better than one big bowl of bran.
• Keep protein first. Pair a fiber food with a protein food, like berries on Greek yogurt or lentils with chicken.

Which foods carry the most fiber in a small portion?

Beans and lentils lead, then berries, pears, chia and oats.

Beans, lentils and edamame bring protein too, which makes them a good fit on a GLP-1. Broccoli, avocado and almonds help as well. Numbers are from USDA FoodData Central. The protein finder shows fiber for 500+ foods.

What should I drink?

Steady sips through the day, more than you think you need.

Keep a bottle you like within reach and sip between meals rather than drinking a lot at once, which can make you feel too full. Ask your care team how much is right for you, especially if you have a heart or kidney condition.

Does moving help?

Yes. Being less active is one of the common causes of constipation.

A short walk after meals is an easy place to start. It also helps with feeling full after eating.

What about supplements and laxatives?

Ask your doctor or pharmacist first.

The advisory and the 2022 expert consensus both mention fiber supplements and laxatives as options. Which one suits you depends on your health and your other medicines, so it’s a question for your care team.

When should I call my doctor?

If constipation lasts, or comes with pain, vomiting or blood.

Questions about your dose are always for your prescriber.

What does a higher-fiber day look like?

Small portions, with a fiber food at each meal and sips in between.

• Breakfast: oatmeal made with milk, topped with raspberries and a spoon of chia
• Lunch: lentil soup with a little chicken or tofu
• Snack: a pear and a few almonds
• Dinner: salmon with broccoli and a small scoop of beans
• Through the day: water, tea or clear broth

Imi plans meals like this for you each week. For the bigger picture, see eating well on a GLP-1 and queasy days.